Ion channels allow things to cross the membrane
I believe the answer is D. The atmosphere, different layers of the atmosphere can help in different ways! The stratosphere helps protect us from the sun's rays; The Mesophere is what helps protect us from meteorites! It's so cold that they burn up in that area.
The answer will be 25.92 L for 17.0 c
The p sublevel holds 6 electrons because it has 3 orbitals.
